Effect Of Endoplasmic Reticulum Stress On Hydrogen Peroxide Induced Retinal Ganglion Cells Apoptosis

Background：The optic nerve damage is a common and intractable diseases of the eye,studies have shown that a common pathological changes is the apoptosis andnecrosis of retinal ganglion cells (RGCs). Apoptosis has its special signalingpathway, According to the summarize of the present study, the main Signaltransduction pathways are: death receptor activation (extrinsic pathway),mitochondrial damage and endoplasmic reticulum stress-induced apoptosissignaling pathways (intrinsic pathway), the endoplasmic reticulum stresspathway of apoptosis research is the hotspot in recent years. Endoplasmicreticulum unfolded protein aggregation can sense three main receptors,they areER transmembrane protein, that are PERK、IRE1α and ATF6. When theendoplasmic reticulum stress persists, Will result in the unfolded proteinresponse,they will active the downstream signal molecules,likeCHOP/GADD153、JNK、caspase-12and GSK-3/3β etc. Finally, the role ofchromatin in the nucleus, regulation of gene transcription, synthesis the relatedproteins, to complete the process of apoptosis. Which caspase-12is located inthe outer membrane of ER, it is a key factor in the endoplasmic reticulumstress-mediated apoptosis signaling pathway conduction, it will not be activatedin death receptor and mitochondrial apoptotic pathway, is the specific signalingmolecules of ERS.Objective：This study aims to investigate whether the endoplasmic reticulum stressinvolved in hydrogen peroxide-induced apoptosis of retinal ganglion cells，Toprovide theoretical and experimental basis for the protecting of the optic nerve. Methods：The RGC-5cell line is stimulated by various concentrations of H2O2, toestablish a model of apoptosis in vitro. Firstly, the apoptotic morphology ofRGCs was observed by DAPI staining method，to screen out the suitable H2O2concebtration. And then, the Flow cytometry was conducted to evaluate thepercentage of apoptotic role of RGCs in different time periods. Finally,WesternBlot analysis were used to assess the expression of Caspase-12、3、9in RGC-5incubated with H2O2.Results：DAPI staining and the Flow cytometry showed that the suitableconcentration of H2O2is500μmol/L,and the rate of cell apoptosis is biggest on8h,the difference was statistically significant (P<0.05); Western Blot resultsshowed that,with the cells apoptosising,the expression of cleaved-Caspase-12are increased, and the expression of procaspase-12are decreased, theexpression of procaspase-9、3are increased, the difference was statisticallysignificant compared with the control group (P <0.05).Conclusion：The apoptosis of RGC-5is induced by low concentrations of H2O2, lowconcentrations of H2O2lead to cells necrosis；ERS are involved in apoptoticsignal transduction by low concentrations of hydrogen peroxide-inducedapoptosis on RGC-5.